Chemokines in bronchoalveolar lavage fluid in summer-type hypersensitivity pneumonitis.

Hypersensitivity pneumonitis (HP) is a granulomatous interstitial lung disease caused by the inhalation of a variety of antigens and is characterized by a dramatic accumulation of inflammatory cells, including neutrophils, lymphocytes and macrophages, in the lung. The mechanisms implicated in the inflammatory cell recruitment observed in hypersensitivity pneumonitis are unknown. We examined the concentrations of two important chemokines, interleukin-8 (IL-8) and monocyte chemoattractant protein-1/monocyte chemotactic and activating factor (MCP-1/MCAF), in the bronchoalveolar lavage fluid (BALF) of patients with summer-type hypersensitivity pneumonitis (n = 8), and compared them with those in patients with sarcoidosis (n = 13) and with controls (n = 8). In the BALF of summer-type hypersensitivity pneumonitis, the levels both of IL-8 and MCP-1 were significantly increased compared with levels measured in control subjects. On the other hand, compared to the control value, the MCP-1 level in the BALF of the sarcoidosis patients was significantly increased, but IL-8 was only slightly and nonsignificantly increased. Since IL-8 is a chemoattractant for neutrophils and T-lymphocytes, whereas MCP-1 acts mainly on monocytes/macrophages, our findings may indicate that these two chemokines participate in the cellular accumulation observed in hypersensitivity pneumonitis.